The hippocampus is one part of the limbic system in the brain. The limbic system is a group of brain structures that surround the brain stem. The brain structures that make up this system play an important role in the experience of certain emotions (for example, fear and anger, motivations, and memory).
The hippocampus is specifically responsible for our ability to store and retrieve memories. People who have damage to their hippocampus may experience difficulty or inability to store and/or recall information. Along with other limbic structures, the hippocampus also plays a role in a person's ability to overcome fear responses. Because of this, the hippocampus has been identified as a brain structure that may be important to understanding the development of PTSD and other anxiety disorders.